https://www.wsj.com/articles/israel-conferred-with-u-s-on-strike-in-syria-to-target-iranian-war-gear-1524001066A little bit later come the admission:
The Israeli military targeted an advanced Iranian air-defence system at the T4 base in Syria last week and not just attacked a drone deployment base.
A senior Israeli military official admitted that Israel targeted T4, adding that “it was the first time we attacked live Iranian targets – both facilities and people.”Updated Apr 23, 2018, 5:57 PM